Treatment of tall oil



Patented May 11, 1948 2,441,197 TREATMENT or TALL on.

Nicholas L. Kalman,

ford, N. J.,

deceased, late of Rutherby Anna Kalman, executrix, Newark,

N. J., assignor to ltidbo Laboratories, 1110., Paterson, N. J., a corporation of New Jersey No Drawing. Applic Serial No.

' Claims. 1

This invention relates to treatment of tall oil and is especially concerned with a method by which crude tall oil may be treated to derive therefrom an oily product having a number of altered and improved physical and chemical characteristics which adapt the product to a number of commercial uses for which the crude material is not well suited.

As is known, tall 011 is a waste or by-product of the process of paper manufacture, the crude tall oil comprising a sludgy mass containing fatty acid and rosin constituentsythe latter of which manifests a marked tendency to crystallize, and

the mass being characterized by a particularly obnoxious odor and a very dark color.

Aside from the dirt, impurities, color bodies, sterols, etc., crude tall oil consists essentially of rosin acids and of fatty acids, the latter of which are similar in general properties to the fatty acids of semi-drying fatty oils. The rosin and fatty acid constituents taken together comprise roughly 90% of the tall oil, and each of these two major constituents comprises approximately one-half of the material, excluding the impurities, etc,

A number of treatment processes have been proposed for refining, purifying and the like, of crude tall oil and in some cases the prior treatments improved the color, in others they improved the odor and in still others the tendency to crystallize has been more or less completely overcome. However, although prior known treatments have been effective in one or two of the respects just mentioned, no one prior treatment has been thoroughly effective in all three of the respects referred to. In addition, for certain purposes it is of distinct advantage to alter the chemical characteristics of crude tall oil, and the process of the present invention color and odor but additionally brings about certain other changes of desirable character as will further appear.

Briefly, in a typical treatment according to the invention, the tall oil is heated for a period of about three hours at about 300 C. in the presence of ortho-phosphoric acid, after which the tall oil is distilled, preferably under high vacuum. In this typical treatment the phosphoric acid performs several functions. phosphoric acid reacts with various impurities, color bodies, etc., to convert the same to a form in which they are non-distillable. The phosphoric acid also serves as an agent promoting decarboxylatlon of rosin acids present. The subsequent distillation, which in a typical case is efis not only highly I effective in eliminating sludging and improving In the first place, the

. especially effective treating agent.

ation June 9, 1945,

fected at an absolute pressure in the neighborhood of 5 mm. Hg and is carried up to a temperature of about 225 0., results in the distilling over of the major portion of the fatty acid, decarboxylated rosin and the remaining rosin acids,- leaving a residue consisting of substantially undistillable reaction products of the phosphoric acid with impurities, color bodies, polymers, etc. The distillate, in a typical case, comprises about '70 to of the crude tall oil taken for treatment, the distillate being an oily substance of pale yellow color and fatty or fruity odor. In many cases the distillate manifests no tendency to develop crystals even after standing for extended periods of time. The treatment conditions may be controlled to vary the extent of decarboxylation 0f rosin acids. Preferably the decarboxylation is such as to yield a product having an acid value not above about 130, which compares with -170 for crude tall oil.

Because of various of the characteristics mentioned above, the total distillate or separated con stituents thereof are well adapted to many commercial uses such, for example, as plasticizers for plastics, coating compositions, etc.

Another important advantage of the product produced in accordance with the method of this invention is that the fatty acid component of the distillate is essentially unchanged by the treatment, and therefore, upon separation of the acid constituents from the others, this component can be used for any purposes for which semi-drying fatty acids are useful. The rosin hydrocarbon component is also useful for many industrial puroses.

Of the treating agents which may be employed according to this invention, ortho-phosphoric acid or its anhydride constitutes a typical and However, other phosphorus compounds may also be used, particularly the acids, oxides, sulfides, halides (especially chlorides), and oxychlorides. Typical agents are as follows:

Pym-phosphoric acid Hypo-phosphorous acid Ortho-phosphorous acid Phosphorus pentasulilde Phosphorus trichloride Phosphorus pentachloride Phosphorus oxychloride in order to effect any substantial present.

The quantity or treatment agent employed may varyfrom about 0.5% up to about 10%, or somewhat higher, although increase of the quantity above about 10% ordinarily does not manifest any further improvement in decarboxylation or decolorizing action. At the higher percentages of reagent used the temperature 01' pretreatment should preferably be kept somewhat below 300 0. Usually from about 1% to 3%. for instance 2%. is sufficient to bring about quite extensive changes in properties of the crude tall oil. It is of advantage not to exceed about since 3 decarboxylation of resin acids 4 EXAMPLES Couraaarrvr: EXAMPLES 1-9 In this group of examples crude tall oil was 5 first pretreated with a number of diflerent phosphorus compounds, 2% of the treating agent being used (except for the two examples noted in the following table). The treatment temperature in each example was 300 C. and the time of treatment was 3 hours. In each case distillation was eflected at a pressure between about 1 and 8 mm. Hg, the temperature being carried up to the neighborhood of 200 C. or somewhat higher.

Various of the characteristics of the products above this percentage a greater degree of polymof these examples are given in Table I just below. erization takes place, thereby reducing the dis- In the table there is also included reference to a 'tillat'e yield. blank" experiment, representing a heat treat- The treatment temperature to be employed in ment and distillation effected without the emthe presence of the treating agent may vary ployment of a treating agent. Still further, at anywhere from about 250 C. to about 350 C., a go the bottom of the table data is given for crude particularly eiIective range being from 275 C. to

untreated tall oil, for purposes of comparison.

Table L-Vartous treating agents Phosphorus pentoxide (p Phosphorus genius Plfioephorus d Foul.

i 2.6% agent used-mil others 2%.

325 C. From about 1 to 5 hours is ordinarily sufilcient for thetime of treatment. i. e., for the time of treatment preceding" distillation.

In efi'ecting distillation, the pretreated material is heated under vacuum, preferably below about mm. Hg. A small forerun is usually taken and set aside, since it contains some water and a constituent of foul odor. The main distillate, at from 1-10 mm. Hg comes over between about 130 C. and about 240 C.

As an alternative to the procedure of first pretreating the tall oil with the phosphoric acid for a period of several hours and thereafter distilling, the distillation may be commenced at or toward the beginning Table IL-Variation in percent 5 Other minor variations of the heat treatment with The products of all of the above examples were clear oils and many showed no tendency to crystallize even after prolonged standing.

COMPARATIVE ExamrLss 10-13 This group of examples were all performed under similar conditions except for a, variation in the percentage of ortho-phosphoric acid used.

in conditions of treatment are indicated in Table II just below.

In general the examples of this group were carried out in the same manner as described above in connection with Examples 1-9 inclusive. The data for Example 1 from Table I is also included in Table II for comparison.

of treating agent mike-phosphoric acid Er. No. Per cent 23 Acid Color Odor Iodine Blank..... None 4 160 Light Amber- Acidic Hiibl I00 10 l 3 121 Yellow Fatt 168 2 3 132 Pale Yellow.-

3 5 105 Yell 1 Pretreaied at 275 C.Bll others at 300 C.

phosphoric acid, for example when the temperature has been raised to about C., the distillation being continued during rise in temperature to about 240 C. and odor and the extent of decarboxylation, however, when proceeding in this way-are not as great as where the tall oil is pretreated for several hours prior to the distillation. The pretreatment is therefore the preferred practice.

The improvement in color 7 COMPARATIVE EXAMPLE 14 Comfiaharrvn Exmrm 15 This example illustrates the alternative treat ment procedure where distillation is commenced without any extended period of pretreatment with the treating agent. The treating agent employed was ortho-phosphoric acid, 2% being used and the vacuum was applied for distillation in the neighborhood of 150 C., the temperature of the distillate vapor being carried up to 228 C. The treatment was efiected at a pressure of 1-2 mm. Hg and yielded a distillate comprising a clear, yellow oily material of fatty odor, having an acid value of 95 and Hiibl iodine value of 130.

It is claimed:

1. A method for treating tall oil comprising heating the tall oil in the presence of from 0.5% to 10% of an agent selected from the class consisting of phosphorous acids, oxides, sulfides, chlorides, and oxychlorides, at a temperature between about 250 C. and about 350 C.. and distilling the volatile constituents oi. tall oil to recover a product essentially consisting of a mixture of fatty acids and rosin hydrocarbons.

2. A method for treating tall oil comprising heating the tall oil in the presence of from 1% to 3% of an agent selected from the class consisting of phosphorus acids, oxides, sulfides, chlorides, and oxy'chlori'des, at a temperature between about 250 C. and about 350 C., and distilling the volatile constituents of tall 011 to recover a product essentially consisting of a mixture of fatty acids and rosin hydrocarbons.

3. A method according to claim 2 in which the distillation isefiected concurrently with the treatment with said phosphorus agent.

4. A method according to claim 2 in which the tall oil is treated with said phosphorus agent for at least 1 hour prior to the distillation thereof.

5. A method according to claim 2 in which the treating agent isa phosphorus acid.

6. A method according to claim 2 in which the treating agent is a phosphorus oxide.

7. A method according to claim 2 in which the treating agent is a phosphorus chloride.

8. A method according to claim 2 in which the treating agent is ortho-phosphoric acid.

9. A method according to claim 2 in which the treating agent is phosphorus pentoxide.

10. A method according to claim 2 in which the treating agent is phosphorus trichloride.

ANNA KALMAN, Executria: of the Estate of Nicholas L. Kalman,

Deceased.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

